In view of large time delay and uncertainty of the main steam temperature system in a power plant, combining with internal model controller, a control method based on adaptive PSD is proposed. The advanced control algorithms have the advantages of the simple algorithm and the small calculating amount. Compared with the conventional cascade PID control system, the simulation results show that the self-adaptive PSD control system has better control performance on adaptability, such as to decrease the overshoot, shorten the settling time, accelerate the response, etc.